Six months ago I ventured in this space that the Democratic position on the war in Iraq was the single most critical question in U.S. politics. The statement made on Monday by John Kerry is the climactic event in this matter. Sen. Kerry said that notwithstanding all that is known now, whatever have been the developments in the past year, if he had it to do again, he'd vote as he did: in favor of giving the president the power he requested, before going on to wage war in Iraq.

Kerry made this faintly more tolerable to the anti-war segment by saying that he was pleading, after all, a point of constitutional rectitude: The president should have the power inherent in his role as commander in chief. Kerry did not trouble to ponder what it is the Constitution was talking about when it said that only Congress could declare war. Never mind; we don't declare wars any more, we just fight.

But outstanding in political meaning was less what Kerry said about standing by his vote than what he said about the long-term commitment we have undertaken. Surely he would pledge to reduce our troops in Iraq by next summer, even if he wasn't prepared to simply call them home, as Democratic contender Howard Dean had demanded.

Well, here is how Kerry put it: "I believe if you do the kind of alliance-building that is available to us, that it is appropriate to have a goal of reducing our troops over that period of time. Obviously we have to see how events unfold."

Indeed. How events unfold. What events?

Here is where Kerry underwrote the Iraq venture in terms extraordinarily comprehensive. "The measurement has to be, as I've said all along, the stability of Iraq, the ability to have the elections, and the training and transformation of the Iraqi security force itself." Get from your paper supplier the thinnest sheet in the inventory, and you won't succeed in wedging it between the Republican and the Democratic position on the nature of our strategic objectives in Iraq.

This is reassuring, by most lights. The nation is at war; it is comforting that both political parties support the war. What is astonishing is that the entire vector of U.S. politics is here affected. The Democratic Party, through its leaders, has expressed itself with progressive force against the Iraq war. It was certainly expected that Democratic challenger John Kerry would pound home his criticisms of President Bush's policies.

Public support for the war has diminished in the 17 months since we went in. This reflects the absence of the weapons of mass destruction, the disaffection of some of our allies, the intransigence of the insurgents, and the mounting fatalities. The approval of the war has reduced from 73 percent early on to about 49 percent, and the dynamics of democratic government would suggest that the Democratic challenger would proceed, if not to deconstruct the war, at least to criticize the conduct of it and the assumptions associated with it.

Kerry is saying that our commitments continue until democratic elections in Iraq are held. This is a dream, though not, we like to think, extravagant. The New York Times has published an update on concrete questions, from which we learn that there is bad news (the insurgents have risen from 5,000 in April to 20,000 today), but that estimates of support for the new Iraqi government are at 68 percent, and 80 percent of Iraqis believe that life will improve under the new government. Already there is an increase in oil production and in electricity.

It is an honorable thing for John Kerry to do, to associate himself so fully with the whole Iraq enterprise. Bush can take satisfaction from that endorsement, and critics of the war will have to exert themselves in other ways than merely to support the election of John Kerry.